The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Bin Chen - One of the best experts on this subject based on the ideXlab platform.
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (Tg), while adding sorbitol also increased mobility and lowered Tg. Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as g...
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (T(g)), while adding sorbitol also increased mobility and lowered T(g). Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as glucose.
Craig P Sherwin - One of the best experts on this subject based on the ideXlab platform.
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (Tg), while adding sorbitol also increased mobility and lowered Tg. Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as g...
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (T(g)), while adding sorbitol also increased mobility and lowered T(g). Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as glucose.
Daniel Blankschtein - One of the best experts on this subject based on the ideXlab platform.
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j cosmet sci 59 263 289 july august 2008 visualization and quantification of skin barrier perturbation induced by surfactant Humectant systems using two photon fluorescence microscopy
International Journal of Cosmetic Science, 2009Co-Authors: Saswata Ghosh, Daekeun Kim, Daniel BlankschteinAbstract:Synopsis In order to visualize the effects of aqueous surfactant–Humectant systems on the skin barrier, an in vitro two-photon fluorescence microscopy (TPM) study, including dual-channel visualization, was carried out. TPM is a non-invasive imaging technique based on two-photon induced nonlinear excitations of fluorophores, with the capability for deep-tissue imaging (up to several hundred micrometers). The following aqueous solutions of surfactants, a Humectant, and a surfactant + Humectant mixture that contacted pig full-thickness skin (p-FTS) were studied: (i) a harsh surfactant solution—sodium dodecyl sulfate (SDS) (1 wt%); (ii) a harsh surfactant + Humectant solution—SDS (1 wt%) + glycerol (10 wt%); (iii) a mild surfactant solution—sodium cocoyl isethionate (SCI) (1 wt%); (iv) a control solution—phosphate-buffered saline (PBS); and (v) a Humectant solution—glycerol (10 wt%). Sulforhodamine B (SRB), a hydrophilic fluorescent probe, was used to visualize the effects of aqueous contacting solutions i–v on the skin barrier morphology. The results of the TPM visualization study revealed that SDS induces corneocyte damage by denaturing keratins and creating intracorneocyte penetration pathways. On the other hand, SDS + glycerol did not significantly induce corneocyte damage. The dual-channel TPM images corresponding to aqueous contacting solutions iii–v showed low SRB penetration into the corneocytes, as well as localization of the SRB probe within the lipid bilayers surrounding the corneocytes of the SC. Through a quantification of the amount of SRB that penetrated into the skin as a function of skin depth, we found that adding glycerol to an SDS aqueous contacting solution can significantly reduce the SDS-induced penetration depth of SRB, which provides evidence of the ability of glycerol to mitigate SDS-induced skin barrier perturbation. The distribution of SRB in the p-FTS samples was analyzed using a theoretical model that quantified changes in the skin aqueous pore characteristics induced by aqueous contacting solutions i, ii, iii, and v, relative to aqueous contacting solution iv, the control. The results of the theoretical model indicate the following ranking order in the extent of perturbation to the skin aqueous pores (from the highest to the lowest): i > ii > iii > iv > v. The development of such an in vitro visual ranking methodology, including quantification using TPM, can potentially reduce many costly in vivo screening procedures, thereby significantly reducing the cost and time-to-market of new cosmetic formulations containing surfactants and Humectants.
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j cosmet sci 58 599 620 november december 2007 ranking of aqueous surfactant Humectant systems based on an analysis of in vitro and in vivo skin barrier perturbation measurements
International Journal of Cosmetic Science, 2008Co-Authors: Saswata Ghosh, Sidney Hornby, Gary Grove, Charles Zerwick, Yohini Appa, Daniel BlankschteinAbstract:Accepted for publication July 19, 2007 Synopsis We propose that skin electrical current measurements can be used in vitro to effectively rank aqueous solutions containing surfactants and Humectants (the enhancer) contacting the skin, relative to a PBS aqueous solution (the control) contacting the skin, based on their ability to perturb the skin aqueous pores. Specifically, we develop an in vitro ranking metric using the increase in the skin electrical current induced by an enhancer relative to the control. Aqueous contacting solutions containing (i) surfactants [SDS (sodium dodecyl sulfate)] and C12E6 [dodecyl hexa (ethylene oxide)], (ii) Humectants (glycerol and propylene glycol), and (iii) a control (PBS) were studied. Utilizing the new in vitro ranking metric, these aqueous contacting solutions were ranked as follows (from the mildest to the harshest): glycerol < propylene glycol < PBS < C12E6 < SDS. In order to further develop this ranking methodology, which can potentially lead to the reduction, or elimination, of costly and time-consuming procedures, such as human and animal testing and trial-and-error screening in vivo, it was important to correlate the findings of the in vitro ranking metric with direct in vivo skin barrier measurements. For this purpose, in vivo soap chamber measurements, including transepidermal water loss, visual skin dryness, and chromameter erythema measurements, were carried out on human volunteers using the aqueous surfactant–Humectant solutions described above. The results of these in vivo measurements were found to be consistent with the ranking results obtained using the in vitro ranking metric. To further explore the validity of our model and to verify the skin barrier mitigating effect of glycerol, in vivo soap chamber measurements were carried out for aqueous SDS solutions containing 10 wt% added glycerol. These in vivo measurements support our recent in vitro finding that glycerol reduces the average radius and the pore number density of the skin aqueous pores, such that SDS micelles are hindered from penetrating into the skin and inducing skin barrier perturbation.
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visualization and quantification of skin barrier perturbation induced by surfactant Humectant systems using two photon fluorescence microscopy
Journal of Cosmetic Science, 2008Co-Authors: Saswata Ghosh, Daekeun Kim, Daniel BlankschteinAbstract:In order to visualize the effects of aqueous surfactant-Humectant systems on the skin barrier, an in vitro two-photon fluorescence microscopy (TPM) study, including dual-channel visualization, was carried out. TPM is a non-invasive imaging technique based on two-photon induced nonlinear excitations of fluorophores, with the capability for deep-tissue imaging (up to several hundred micrometers). The following aqueous solutions of surfactants, a Humectant, and a surfactant+Humectant mixture that contacted pig full-thickness skin (p-FTS) were studied: (i) a harsh surfactant solution-sodium dodecyl sulfate (SDS) (1 wt%); (ii) a harsh surfactant+Humectant solution-SDS (1 wt%) + glycerol (10 wt%); (iii) a mild surfactant solution-sodium cocoyl isethionate (SCI) (1 wt%); (iv) a control solution-phosphate-buffered saline (PBS); and (v) a Humectant solution-glycerol (10 wt%). Sulforhodamine B (SRB), a hydrophilic fluorescent probe, was used to visualize the effects of aqueous contacting solutions i-v on the skin barrier morphology. The results of the TPM visualization study revealed that SDS induces corneocyte damage by denaturing keratins and creating intracorneocyte penetration pathways. On the other hand, SDS+glycerol did not significantly induce corneocyte damage. The dual-channel TPM images corresponding to aqueous contacting solutions iii-v showed low SRB penetration into the corneocytes, as well as localization of the SRB probe within the lipid bilayers surrounding the corneocytes of the SC. Through a quantification of the amount of SRB that penetrated into the skin as a function of skin depth, we found that adding glycerol to an SDS aqueous contacting solution can significantly reduce the SDS-induced penetration depth of SRB, which provides evidence of the ability of glycerol to mitigate SDS-induced skin barrier perturbation. The distribution of SRB in the p-FTS samples was analyzed using a theoretical model that quantified changes in the skin aqueous pore characteristics induced by aqueous contacting solutions i, ii, iii, and v, relative to aqueous contacting solution iv, the control. The results of the theoretical model indicate the following ranking order in the extent of perturbation to the skin aqueous pores (from the highest to the lowest): i > ii > iii > iv > v. The development of such an in vitro visual ranking methodology, including quantification using TPM, can potentially reduce many costly in vivo screening procedures, thereby significantly reducing the cost and time-to-market of new cosmetic formulations containing surfactants and Humectants.
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ranking of aqueous surfactant Humectant systems based on an analysis of in vitro and in vivo skin barrier perturbation measurements
Journal of Cosmetic Science, 2007Co-Authors: Saswata Ghosh, Sidney Hornby, Gary Grove, Charles Zerwick, Yohini Appa, Daniel BlankschteinAbstract:We propose that skin electrical current measurements can be used in vitro to effectively rank aqueous solutions containing surfactants and Humectants (the enhancer) contacting the skin, relative to a PBS aqueous solution (the control) contacting the skin, based on their ability to perturb the skin aqueous pores. Specifically, we develop an in vitro ranking metric using the increase in the skin electrical current induced by an enhancer relative to the control. Aqueous contacting solutions containing (i) surfactants [SDS (sodium dodecyl sulfate)] and C(12)E(6) [dodecyl hexa (ethylene oxide)], (ii) Humectants (glycerol and propylene glycol), and (iii) a control (PBS) were studied. Utilizing the new in vitro ranking metric, these aqueous contacting solutions were ranked as follows (from the mildest to the harshest): glycerol < propylene glycol < PBS < C(12)E(6) < SDS. In order to further develop this ranking methodology, which can potentially lead to the reduction, or elimination, of costly and time-consuming procedures, such as human and animal testing and trial-and-error screening in vivo, it was important to correlate the findings of the in vitro ranking metric with direct in vivo skin barrier measurements. For this purpose, in vivo soap chamber measurements, including transepidermal water loss, visual skin dryness, and chromameter erythema measurements, were carried out on human volunteers using the aqueous surfactant-Humectant solutions described above. The results of these in vivo measurements were found to be consistent with the ranking results obtained using the in vitro ranking metric. To further explore the validity of our model and to verify the skin barrier mitigating effect of glycerol, in vivo soap chamber measurements were carried out for aqueous SDS solutions containing 10 wt% added glycerol. These in vivo measurements support our recent in vitro finding that glycerol reduces the average radius and the pore number density of the skin aqueous pores, such that SDS micelles are hindered from penetrating into the skin and inducing skin barrier perturbation.
And Alon Mccormick - One of the best experts on this subject based on the ideXlab platform.
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (Tg), while adding sorbitol also increased mobility and lowered Tg. Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as g...
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (T(g)), while adding sorbitol also increased mobility and lowered T(g). Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as glucose.
Theodore P. Labuza - One of the best experts on this subject based on the ideXlab platform.
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (Tg), while adding sorbitol also increased mobility and lowered Tg. Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as g...
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cross polarization magic angle spinning nmr to study glucose mobility in a model intermediate moisture food system
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Craig P Sherwin, And Alon Mccormick, Theodore P. Labuza, Bin ChenAbstract:Theories for the chemical stability of foods cite the role of moisture content or water activity in reactant mobility, though mobility has been variously defined. One theory, based on plasticization by moisture, is limited by a lack of research directly linking the mobility of a matrix to the mobility and reactivity of small solute molecules in foods. A cross-polarization/magic angle spinning technique was developed to study glucose rotational mobility in the solid state over a range of water activities and in matrixes with different glass transition temperatures. Data analysis stressed the significance of separating molecular mobility from relaxation time. Results showed that, in a caseinate matrix, compared to a control, adding glycerol yielded the highest glucose mobility and lowest glass transition temperature (T(g)), while adding sorbitol also increased mobility and lowered T(g). Consequently, plasticization by either moisture or these Humectants increases the mobility of small solute molecules such as glucose.
